From what I understand, rear toe-out will make the car pivot more. In a sense making it more unstable. Toe-in makes it more stable.
At the moment I have toe-in the the back and toe-out in front. The toe-out in front improved the turn-in phase at the detriment of straight line and braking stability. To what extend? I don't know, but I will try toe-in in the front on my next alignment to see for myself.